Code P0171 - Mechanic says replaced the MAF, but I'm considering a second opinion
About a week ago after filling up on gas, my 2020 Mazda 3 began revving at high RPM while idling and the engine malfunction warning has been on ever since. I took it to the mechanic, the scanner read code P0171. He cleaned the throttle , checked for vacuum leaks and replaced the spark plugs (they were toasted and I was planning to replace them anyways and figured this would help). He says there are no vacuum leaks. He determined that the MAF is faulty and I also need to replace the thermostat. The MAF is kinda pricey so I decided to clean it myself before committing to the replacement. It drove a little smoother after cleaning but thr RPM was still pretty high while idling. Then I went to fill up on gas again and my car stalled immediately after getting gas. I was afraid my car was dead at the pump. Luckily after a few attempts I was able to get it started and it hasn't stalled since then. It aggravated the usual symptoms though, the revving and all that. My thoughts are, since the problem seems to be triggered and aggravated every time I get gas, if this could maybe be a problem with the fuel system instead of the MAF? Based on what I've described, does this sound like a MAF issue or should I get a second opinion? I'm not mechanically inclined myself so I don't think I'd be able to analyze and diagnose my own fuel system. I just want to be confident in what the issue is before I buy replacement parts.